A vector network analyzer (VNA) is an instrument that measures amplitude and phase properties of electrical networks. VNAs are often used to characterize two-port networks, although networks having a greater number of ports can also be characterized. A VNA having two test ports permits measurement of four S-parameters—S11, S21, S12, and S22. The basic architecture of a VNA typically includes a signal generator, a test set, two or more receivers, and a display unit. The signal generator provides a test signal for the VNA, and the test set routes the signal generator output to the device under test and then to the receivers. A reference channel is also split from the incident wave and routed directly to the receivers to serve as a phase reference. The receivers measure the magnitude and phase of the signal thereby allowing characterization of the electrical network.
Present day VNAs, although sophisticated and armed with a robust array of data processing and display features, do little to minimize phase noise, which may be introduced from the signal generator. Accordingly, it is desirable to provide a VNA that eliminates, or at a minimum, significantly reduces phase noise.
Additionally, other electronic components in numerous RF applications, such as communication, radar, and imaging applications, may benefit from an electronic circuit and method that significantly reduces phase noise.